水轮发电机转子典型机电故障的不平衡磁拉力研究

针对水轮发电机发生转子偏心和转子绕组匝间短路故障产生不平衡磁拉力,进而引起机组强烈振动的情况,通过有限元仿真软件建立一台550MW水轮发电机二维仿真模型,分别对转子动、静偏心故障及转子绕组匝间短路故障进行模拟,计算各故障情况下的不平衡磁拉力,分析转子偏心程度、方向和转子绕组匝间短路程度对不平衡磁拉力大小和方向的影响。结果表明,不论是发生转子偏心故障还是发生转子绕组匝间短路故障,不平衡磁拉力数值均随故障程度的加重而增大,且不平衡磁拉力方向为诊断转子偏心方向和空载情况下匝间短路故障磁极提供帮助。研究成果为未来研究水轮发电机振动现象和故障检测奠定了基础。

Study on Hydro-generator Unbalanced Magnetic Pull under the Typical Electromechanical Faults of Rotor

The rotor eccentricity and rotor winding inter-turn short-circuit fault generated the unbalanced magnetic pull in hydro-generator, which caused the strong vibration of the unit. A two-dimensional simulation model of a 550 MW hydro-generator was established by the finite element simulation software in order to simulate the dynamic and static eccentricity fault of the rotor and rotor winding inter-turn short-circuit fault. The unbalanced magnetic pull under various fault conditions was calculated. The influences of the direction and degree of the rotor eccentricity, the degree of rotor winding inter-turn short circuit on the magnitude and direction of unbalanced magnetic pull were analyzed. Research shows that the values of unbalanced magnetic pull increase with the degree of failure increases whether the rotor eccentricity fault or rotor winding inter-turn short-circuit fault, and the unbalanced magnetic pull direction can be helpful for the diagnosis of rotor eccentric direction and inter-turn short-circuit fault under no-load conditions. The research result lays a foundation for future study of hydro-generator vibration and fault detection.